The invention relates in general to the field of measuring devices and in particular relates to devices that measure level, plumb, acute and obtuse angles.
In prior and present times, measuring 0.degree., 45.degree., and 90.degree. for building construction purposes have required a carpenter's spirit level which contains a module having a bubble in a vial and permanently located in a wooden or metal bar. This well know apparatus gives accurate readings at the level and plumb positions as long as the module remains in good condition, that is, the glass surrounding the module remains unbroken.
Another aspect of the prior art carpenter's level is that for a relatively long unit at least three or more modules are required to satisfy the various positions of the eye when taking a measurement. This type of assembly is somewhat expensive in view of the redundancy of the modules required of prior art devices.
At the present time, electronic levels represent the state of the art in measuring devices. These products measure level, plumb, acute and obtuse angles but are relatively expensive and require periodic battery replacements. They are three to four times the cost that is applied to a conventional wood or metal carpenter's level and, in addition, their accuracy is sometimes questionable because battery and electronic circuitry changes over time effects measurements being taken.
In view of the relatively high price of the electronic modules and the obvious need to protect such a unit from theft, some craftsman prefer and rely upon the conventional wooden or metal carpenter's level.
The present invention is designed to economize the manufacturing costs associated with the well known multi-module carpenter level and at the same time to provide a new version of the carpenter's level with the versatility of the electronic unit.